@Miacis: I'm not necessarily opposed to a different pin for each month, but since it will end up being so often it might be easier to just make one recurring pin.
Post Merge: November 28, 2012, 01:04:01 PM
I have a concept for the pin:
A clock is the pin itself, with Riddler's Question Mark and an exclamation point on it.
The clock to represent the idea of the tournament, the question mark to represent both the mystery theme and the host, and the exclamation point to represent panic.
Maybe instead of just the question mark, Riddler himself. Similar to the Mario pin:
Riddler off center to the right in front of a clock with an exclamation point somewhere.